The present invention relates generally to computerized calendars and to-do lists and more particularly to calendars and to-do lists used on electronic personal organizers and pen-based computer systems.
Computerized personal organizers are becoming increasingly popular with a large segment of the population. Computerized personal organizers tend to be small, lightweight, and relatively inexpensive, and can perform such functions as keeping a calendar, an address and telephone book, a to-do list, etc. While many of these functions can also be provided conventional computer systems, personal organizers are very well suited to the personal organization task due to their small size and portability. Personal organizers are available from such companies as Sharp and Casio of Japan.
A relatively new form of computer, the pen-based computer system, holds forth the promise of a marriage of the power of a general purpose computer with the functionality and small size of a personal organizer. A pen-based computer system is typically a small, hand-held computer where the primary method for inputting data includes a "pen" or stylus. A pen-based computer system is commonly housed in a generally rectangular enclosure, and has a dual-function display assembly providing a viewing screen along one of the planar sides of the enclosure. The dual-function display assembly serves as both an input device and an output device. When operating as an input device, the display assembly senses the position of the tip of a stylus on the viewing screen and provides this positional information to the computer's central processing unit (CPU). Some display assemblies can also sense the pressure of the stylus on the screen to provide further information to the CPU When operating as an output device, the display assembly presents computer-generated images on the screen.
The dual-function display assemblies of pen-based computer systems permit users to operate the computer as a computerized notepad. For example, graphical images can be input into the pen-based computer by merely moving the stylus on the surface of the screen. As the CPL senses the position and movement of the stylus, it generates a corresponding image on the screen to create the illusion that the stylus is drawing the image directly upon the screen, i.e. that the stylus is "inking" an image on the screen. With suitable recognition software, text and numeric information can also be entered into the pen-based computer system in a similar fashion.
Two of the most frequently used functions of a personal organizer are the daily calendar (or schedule) and the to-do list. A user typically selects a schedule or to-do date by means of a keyboard entry or other select button.
A problem with schedules and to-do lists of the prior art is that their user interface tends to be awkward. Personal organizers often require a number of keystrokes to enter the date or range o dates to be viewed. Even computers with windowing systems tend to be awkward because they present the user with a controller in one window and a di play in another window. When in the controller window, the user is locked out of the schedule display window and vice versa. Furthermore, the schedule control window is often displayed on top of the schedule display window, thereby obscuring the schedule information. This two window, modal (i.e. only one window s active at a time) system makes it difficult to easily traverse and browse through he schedule or to-do information.
Another limitation of calendars and to-do lists of the prior art is that the format of the displayed schedule information is limited. Most calendars and to-do lists restrict the display of schedule information to one day at a time or one week at a time. It would be desirable to be able to select other display formats, such as a three day schedule or the schedule for the next four Fridays.
Calendars, to-do lists, and notepad applications of the prior art are not always tightly integrated. They may have different user interfaces, requiring more learning on the part of a user and increasing the chance of user error. Also, if they are not integrated, a user will have to go through the time-consuming process of exiting one application program and starting another. Furthermore, non-integrated application programs often have problems communicating with each other, thereby often requiring the duplicative entry of data.